Questions on the cluster analysis functions of Mathematica, including the Hierarchical Clustering Package.
22
votes
4answers
834 views
Clustering of space-time data
Below is an example of a gaze sequence I recorded during a 3 seconds display. That is, where the eye was at every millisecond. While we should have 3000 points, we are missing some due to blinking.
...
13
votes
3answers
2k views
K-means clustering
In MATLAB, there is a command kmeans() that divides an array into $k$ clusters and calculates the centroid of each cluster.
Is there any command in Mathematica to ...
10
votes
1answer
290 views
Visualize cluster distances in DendrogramPlot
I want to perform a cluster analysis using the HierarchicalClustering package. Is there a way to display the inter-cluster distances in a dendrogram plot?
An ...
10
votes
1answer
279 views
Cluster analysis returns questionable results
A few weeks ago I ran a cluster analysis on some economic data and (unfortunately only) now I found out that some results do not make sense. For instance I analyzed the development of unemployment ...
8
votes
4answers
332 views
data clustering
I have some data set which i would like to partition into 3 groups a:set 1 b: set 2 c: background.
I use FindClusters[] function but as you can see (after ...
8
votes
1answer
140 views
FindClusters for 3D Pancake/Platelet Shapes
I'm looking to properly cluster a dataset of roughly 3 million data points in 3-space. The shapes form closely spaced "clusters" that resemble pancakes.
Here is a downsampled dataset:
...
8
votes
2answers
201 views
Why doesn't FindClusters find any clusters in this case?
I am trying to use FindClusters to segment data points into similar numbers but so far I couldn't get it work for this example:
...
6
votes
1answer
254 views
Clustering adjacent points in 2D
I need to find all clusters of adjacent white points in a binary image. By term "adjacent" I mean that coordinates of two points differ by no more than 1 (i.e. the points ...
6
votes
2answers
195 views
Different highlight for each cluster in DendrogramPlot
Is there any way to have each cluster in the DendrogramPlot highlight in a different color? I've tried the obvious way but it doesn't work:
...
6
votes
0answers
178 views
Cluster a signal into areas of equal intensity
Introduction
I have a greyscale photograph that I want to partition into areas of equal intensity.
This means, that the integral over each partition should be (roughly) equal.
There is no unique ...
5
votes
4answers
322 views
5
votes
1answer
114 views
Clustering a set of points
I have a set of 2D points in the square defined by {-1, -1} and {1, 1}. These points typically form compact groups. I need to ...
5
votes
2answers
238 views
Custom distance metric for agglomerative clustering in Mathematica
Is it possible to have a custom distance metric defined to determine the distance between two clusters in Agglomerative clustering in Mathematica?
I have a 3 dimension data with string values along ...
4
votes
2answers
363 views
Clustering a bivariate data set with Mathematica
I need to partition a bivariate data set into predetermined "n" clusters and, at the same time, to fix the centroid position of each cluster. Is the ...
3
votes
1answer
201 views
Plotting reordered clusters with different colors and joined lines
I would like to show how typical days of energy load (found through clustering of a years worth of data) are spread throughout a year in a single graph with a color for each 'typical day' (or ...
3
votes
0answers
75 views
How to give ClusteringComponents initial values?
I came across a variant of k-means that adds a algorithm to select good starting values called k-means++.
...
3
votes
0answers
99 views
Stopping Agglomerative clustering under a condition in Mathematica
How do I instruct Agglomerative clustering to stop/NOT merging two particular clusters if the distance between the two clusters is larger than a threshold value?
I know that we can implement a custom ...
2
votes
2answers
174 views
Which group of points connects more strongly?
I have two groups of points, and the lenth of them may be different.I want to know which group of points connects more strongly, are there any existing algorithms for this?
Here are two groups of ...
0
votes
1answer
105 views
How does DistanceFunction work with images in ClusteringComponents?
Does anyone know the syntax to DistanceFunction? I am trying to define my own function to use with ClusteringComponents; e.g.,
...
0
votes
0answers
28 views
Import/Export Cluster Object [duplicate]
I want to export and then import back in a cluster object from Agglomerate. After the import, the imported object does not behave as a cluster - for example, ClusterSplit does not recognize it as a ...
0
votes
0answers
65 views
FindClusters not finding the clusters I expect
According to the Mathematica documentation, it seems it should be easy to use FindClusters and a distance function to find closest points (vectors), but in these ...
